Real-World Implementation of a Genotype-Guided P2Y12 Inhibitor De-Escalation Strategy in Acute Coronary Syndrome Patients

CYP2C19 genotype–guided de-escalation from ticagrelor or prasugrel to clopidogrel may optimize the balance between ischemic and bleeding risk in patients with acute coronary syndrome (ACS). This study sought to compare bleeding and ischemic event rates in genotyped patients vs standard care. Since 2015, ACS patients in the multicenter FORCE-ACS (Future Optimal Research and Care Evaluation in Patients with Acute Coronary Syndrome) registry received standard dual antiplatelet therapy (DAPT). Since 2021, genotype-guided P2Y12 inhibitor de-escalation was recommended at a single center, switching noncarriers of the loss-of-function allele CYP2C19∗3 or CYP2C19∗2 from ticagrelor or prasugrel to clopidogrel, whereas loss-of-function carriers remained on ticagrelor or prasugrel. The primary ischemic endpoint, a composite of cardiovascular mortality, myocardial infarction, or stroke, and the primary bleeding endpoint, Bleeding Academic Research Consortium 2, 3, or 5 bleeding, were compared between a genotyped cohort and a cohort treated with standard DAPT after 1 year. Among 5,321 enrolled ACS patients, 406 underwent genotyping compared with 4,915 nongenotyped ACS patients on standard DAPT. In the genotyped cohort, 65.3% (n = 265) were noncarriers, 88.7% (n = 235) of whom were switched to clopidogrel. The primary ischemic endpoint occurred in 5.2% (n = 21) of patients in the genotyped cohort compared to 6.9% (n = 337) in the standard care cohort (adjusted HR: 0.82; 95% CI: 0.53-1.28). The primary bleeding rate was significantly lower in the genotyped cohort compared to the standard care cohort (4.7% vs 9.8%; adjusted HR: 0.47; 95% CI: 0.30-0.76). The implementation of a CYP2C19 genotype–guided P2Y12 inhibitor de-escalation strategy in a real-world ACS population resulted in lower bleeding rates without an increase in ischemic events compared to a standard DAPT regimen.